Interdigitated Eutectic Alloy Foil Anodes for Rechargeable Batteries

Abstract

An interdigitated eutectic alloy (IdEA) foil is presented as a framework for the development of alloy anodes with a capacity that is significantly higher than that of the traditional graphite/copper assembly. It is a simple, low-cost approach that can be applied to a broad range of alloy systems with various working ions such as Li, Na, or Mg.

Zn-Sn Interdigitated Eutectic Alloy Anodes with High Volumetric Capacity for Lithium-Ion Batteries

“…5 Given the complexity and diversity of electrodes investigated in the literature, it is critical that researchers provide measurements of lithiated electrode thickness rather than relying upon theoretically calculated values. [6][7][8][9][10][11][12][13][14] Understanding electrode-level performance is further complicated by the tendency to report capacities normalized to the weight of the active material, discounting the binder and copper current collector. While these inactive components make up only 7% of the volume of a graphite electrode, they can make up $20% of state-of-the-art silicon systems.…”

“…2,16 The Interdigitated Eutectic Alloy (IdEA) anode framework, first described by our group, utilizes a simple rolling mill to produce nanostructured electrodes. 6 Metal alloys are plastically deformed by extensive cold-rolling, elongating them in the rolling direction and refining them in the transverse dimension. When this technique is applied to two-phase metal alloys, the resulting foil morphology is that of interdigitated sub-micron domains of the two constituent phases.…”

“…17 The electrochemical properties of deformed eutectic systems had not been explored until our seminal investigation, where the performance of an interdigitated aluminum-tin structure was first investigated. 6 Zinc makes for an attractive host material in an IdEA implementation, offering significant improvements compared to the exploratory aluminum work. The high density of zinc minimizes inactive volume in the anode, and its low lithiation potential enables significant lithiation of the tin domains without the formation of brittle intermetallics in the supporting conductive matrix.…”

“…22 For comparative purposes, the electrode-level gravimetric and volumetric capacities of recently reported anodes have been included in Figure 3. [6][7][8][9][10][11][12][13][14] Although by no means an exhaustive review, the reported values represent an honest effort by us to calculate capacities of the commercially relevant high-performance anode technologies described in recent literature. Detailed calculations of the reported capacities can be found in Tables S1 and S2.…”

Electrochemical behavior of tin foil anode in half cell and full cell with sulfur cathode

“…They concluded that the poor cycle life is related to an inability to completely remove all the inserted lithium. Recently, an interdigitated eutectic alloy including Sn and aluminum (Al) has been developed as a high capacity anode [21].…”